1. Field of the Invention
The present invention relates to vertical thin film transistors and fabricating methods thereof, and more particularly to vertical thin film transistors which can be formed without a mask and methods of fabricating the same.
2. Description of the Related Art
Thin film transistors may be generally formed on a large area substrate so that they are used in a display device, a printer, a scanner, and a smart card.
The thin film transistor includes a semiconductor pattern, a source electrode, a drain electrode, and a gate electrode. The semiconductor pattern, the source electrode, the drain electrode, and the gate electrode are formed using patterning processes, including photolithography processes.
However, when the thin film transistor is formed using a mask, realization of fine patterns is difficult due to accuracy limitation of the mask and problems (e.g., bending and/or separation of the mask) which occur. Thus, it is necessary to form the thin film transistor without a mask or by use of a minimum number of masks.
The thin film transistors may be classified into a horizontal thin film transistor and a vertical thin film transistor. The horizontal thin film transistor has a channel formed between a source electrode and a drain electrode which are horizontally arranged. The vertical thin film transistor has a channel formed between a source electrode and a drain electrode which are vertically arranged. The vertical thin film transistor has a current flow greater than that of the horizontal thin film transistor. However, realization of the vertical thin film transistor may be difficult so that the vertical thin film transistor may not be easily commercialized.